[Freeipa-users] Re: ssh ProxyCommand in ipa-client causes crash of x2goclient
On Friday, 25 October 2019 11:11:32 CEST Alexander Bokovoy wrote: > On pe, 25 loka 2019, Kees Bakker wrote: > >On 24-10-19 16:12, Alexander Bokovoy wrote: > >>On to, 24 loka 2019, Kees Bakker via FreeIPA-users wrote: > >>>Hey, > >>> > >>>With x2go [1] you can start a remote desktop. Going from UNIX (client) to > >>>UNIX (server) it will use SSH behinds the scenes. > >>> > >>>However, on a IPA client the x2goclient command fails with a segfault > >>>(somewhere in a ssh library). This is caused by the modified > >>>/etc/ssh/ssh_config. More specifically this > >>> > >>>ProxyCommand /usr/bin/sss_ssh_knownhostsproxy -p %p %h > >>> > >>>When you disable this line the x2go connection succeeds. > >>> > >>>[1] https://wiki.x2go.org/doku.php > >> > >>If you could install debug packages and generate a backtrace, that would > >>be great as it would help to understand where it happens. Thanks in > >>advance! > > > >Hey Alexander, > > > >The segfault is in a library of the libssh-4 package. I don't know if that > >is something you wanted to be involved with. Anyway, here is the stack > >strace of the segfault. > Thanks. So the crash is in ssh_poll_set_events(). Andreas, do you have > any ideas? Where is libssh installed from? It looks like this is libssh 0.8.0. > > >segfault at 4 ip 7f6e7e0d5eeb sp 7f6e64e6ea88 error 6 in > >libssh.so.4.5.0 > > > >After installing the dgbsym package and running from gdb I could get a > >stack trace > > > >Thread 6 "SshMasterConnec" received signal SIGSEGV, Segmentation fault. > >[Switching to Thread 0x7fffdf1a0700 (LWP 14736)] > >0x77b89eeb in ssh_poll_set_events (p=0x7fffd40076b0, events=4) at > >./src/poll.c:349 349./src/poll.c: No such file or directory. > >(gdb) where > >#0 0x77b89eeb in ssh_poll_set_events (p=0x7fffd40076b0, events=4) > >at ./src/poll.c:349 #1 0x77b8d3c8 in ssh_socket_unbuffered_write > >(len=, buffer=, s=0x7fffd4003850) at > >./src/socket.c:574 > >#2 ssh_socket_nonblocking_flush (s=s@entry=0x7fffd4003850) at > >./src/socket.c:667 #3 0x77b8d4c4 in ssh_socket_write > >(s=0x7fffd4003850, buffer=, len=len@entry=64) at > >./src/socket.c:628 > >#4 0x77b846c3 in ssh_packet_write (session=0x7fffd4004bc0, > >session=0x7fffd4004bc0) at ./src/packet.c:1316 #5 packet_send2 > >(session=session@entry=0x7fffd4004bc0) at ./src/packet.c:1386 #6 > >0x77b85315 in ssh_packet_send > >(session=session@entry=0x7fffd4004bc0) at ./src/packet.c:1411 #7 > >0x77b72d69 in channel_write_common (channel=0x7fffd40112e0, > >data=0x7fffdf11fce0, len=6, is_stderr=0) at ./src/channels.c:1357 > >#8 0x55640cc3 in ?? () > >#9 0x55644745 in ?? () > >#10 0x7581de3c in ?? () from > >/usr/lib/x86_64-linux-gnu/libQtCore.so.4 #11 0x7558b6db in > >start_thread (arg=0x7fffdf1a0700) at pthread_create.c:463 #12 > >0x74d1388f in clone () at > >../sysdeps/unix/sysv/linux/x86_64/clone.S:95 -- Andreas Schneider a...@samba.org Samba Team www.samba.org GPG-ID: 8DFF53E18F2ABC8D8F3C92237EE0FC4DCC014E3D ___ FreeIPA-users mailing list -- freeipa-users@lists.fedorahosted.org To unsubscribe send an email to freeipa-users-le...@lists.fedorahosted.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedorahosted.org/archives/list/freeipa-users@lists.fedorahosted.org
[Freeipa-users] Re: ssh ProxyCommand in ipa-client causes crash of x2goclient
On 25-10-19 13:09, Andreas Schneider wrote: On Friday, 25 October 2019 11:11:32 CEST Alexander Bokovoy wrote: On pe, 25 loka 2019, Kees Bakker wrote: On 24-10-19 16:12, Alexander Bokovoy wrote: On to, 24 loka 2019, Kees Bakker via FreeIPA-users wrote: Hey, With x2go [1] you can start a remote desktop. Going from UNIX (client) to UNIX (server) it will use SSH behinds the scenes. However, on a IPA client the x2goclient command fails with a segfault (somewhere in a ssh library). This is caused by the modified /etc/ssh/ssh_config. More specifically this ProxyCommand /usr/bin/sss_ssh_knownhostsproxy -p %p %h When you disable this line the x2go connection succeeds. [1] https://wiki.x2go.org/doku.php If you could install debug packages and generate a backtrace, that would be great as it would help to understand where it happens. Thanks in advance! Hey Alexander, The segfault is in a library of the libssh-4 package. I don't know if that is something you wanted to be involved with. Anyway, here is the stack strace of the segfault. Thanks. So the crash is in ssh_poll_set_events(). Andreas, do you have any ideas? Where is libssh installed from? It looks like this is libssh 0.8.0. It's Ubuntu 18.04.3 and the libraries are from the normal distribution source. https://packages.ubuntu.com/search?keywords=libssh # dpkg -l libssh\*|cat Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) ||/ Name Version Architecture Description +++-=-==--=== ii libssh-4:amd64 0.8.0~20170825.94fa1e38-1ubuntu0.2 amd64 tiny C SSH library (OpenSSL flavor) ii libssh-4-dbgsym:amd64 0.8.0~20170825.94fa1e38-1ubuntu0.2 amd64 debug symbols for libssh-4 un libssh-dbg (no description available) ii libssh-gcrypt-4:amd64 0.8.0~20170825.94fa1e38-1ubuntu0.2 amd64 tiny C SSH library (gcrypt flavor) ii libssh2-1:amd64 1.8.0-1 amd64 SSH2 client-side library # apt policy libssh-4 libssh-4: Installed: 0.8.0~20170825.94fa1e38-1ubuntu0.2 Candidate: 0.8.0~20170825.94fa1e38-1ubuntu0.2 Version table: *** 0.8.0~20170825.94fa1e38-1ubuntu0.2 500 500 http://nl.archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages 500 http://security.ubuntu.com/ubuntu bionic-security/main amd64 Packages 100 /var/lib/dpkg/status 0.8.0~20170825.94fa1e38-1build1 500 500 http://nl.archive.ubuntu.com/ubuntu bionic/main amd64 Packages segfault at 4 ip 7f6e7e0d5eeb sp 7f6e64e6ea88 error 6 in libssh.so.4.5.0 After installing the dgbsym package and running from gdb I could get a stack trace Thread 6 "SshMasterConnec" received signal SIGSEGV, Segmentation fault. [Switching to Thread 0x7fffdf1a0700 (LWP 14736)] 0x77b89eeb in ssh_poll_set_events (p=0x7fffd40076b0, events=4) at ./src/poll.c:349 349./src/poll.c: No such file or directory. (gdb) where #0 0x77b89eeb in ssh_poll_set_events (p=0x7fffd40076b0, events=4) at ./src/poll.c:349 #1 0x77b8d3c8 in ssh_socket_unbuffered_write (len=, buffer=, s=0x7fffd4003850) at ./src/socket.c:574 #2 ssh_socket_nonblocking_flush (s=s@entry=0x7fffd4003850) at ./src/socket.c:667 #3 0x77b8d4c4 in ssh_socket_write (s=0x7fffd4003850, buffer=, len=len@entry=64) at ./src/socket.c:628 #4 0x77b846c3 in ssh_packet_write (session=0x7fffd4004bc0, session=0x7fffd4004bc0) at ./src/packet.c:1316 #5 packet_send2 (session=session@entry=0x7fffd4004bc0) at ./src/packet.c:1386 #6 0x77b85315 in ssh_packet_send (session=session@entry=0x7fffd4004bc0) at ./src/packet.c:1411 #7 0x77b72d69 in channel_write_common (channel=0x7fffd40112e0, data=0x7fffdf11fce0, len=6, is_stderr=0) at ./src/channels.c:1357 #8 0x55640cc3 in ?? () #9 0x55644745 in ?? () #10 0x7581de3c in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4 #11 0x7558b6db in start_thread (arg=0x7fffdf1a0700) at pthread_create.c:463 #12 0x74d1388f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 ___ FreeIPA-users mailing list -- freeipa-users@lists.fedorahosted.org To unsubscribe send an email to freeipa-users-le...@lists.fedorahosted.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedorahosted.org/archives/list/freeipa-users@lists.fedorahosted.org
[Freeipa-users] Re: ssh ProxyCommand in ipa-client causes crash of x2goclient
On pe, 25 loka 2019, Kees Bakker wrote: On 24-10-19 16:12, Alexander Bokovoy wrote: On to, 24 loka 2019, Kees Bakker via FreeIPA-users wrote: Hey, With x2go [1] you can start a remote desktop. Going from UNIX (client) to UNIX (server) it will use SSH behinds the scenes. However, on a IPA client the x2goclient command fails with a segfault (somewhere in a ssh library). This is caused by the modified /etc/ssh/ssh_config. More specifically this ProxyCommand /usr/bin/sss_ssh_knownhostsproxy -p %p %h When you disable this line the x2go connection succeeds. [1] https://wiki.x2go.org/doku.php If you could install debug packages and generate a backtrace, that would be great as it would help to understand where it happens. Thanks in advance! Hey Alexander, The segfault is in a library of the libssh-4 package. I don't know if that is something you wanted to be involved with. Anyway, here is the stack strace of the segfault. Thanks. So the crash is in ssh_poll_set_events(). Andreas, do you have any ideas? segfault at 4 ip 7f6e7e0d5eeb sp 7f6e64e6ea88 error 6 in libssh.so.4.5.0 After installing the dgbsym package and running from gdb I could get a stack trace Thread 6 "SshMasterConnec" received signal SIGSEGV, Segmentation fault. [Switching to Thread 0x7fffdf1a0700 (LWP 14736)] 0x77b89eeb in ssh_poll_set_events (p=0x7fffd40076b0, events=4) at ./src/poll.c:349 349 ./src/poll.c: No such file or directory. (gdb) where #0 0x77b89eeb in ssh_poll_set_events (p=0x7fffd40076b0, events=4) at ./src/poll.c:349 #1 0x77b8d3c8 in ssh_socket_unbuffered_write (len=, buffer=, s=0x7fffd4003850) at ./src/socket.c:574 #2 ssh_socket_nonblocking_flush (s=s@entry=0x7fffd4003850) at ./src/socket.c:667 #3 0x77b8d4c4 in ssh_socket_write (s=0x7fffd4003850, buffer=, len=len@entry=64) at ./src/socket.c:628 #4 0x77b846c3 in ssh_packet_write (session=0x7fffd4004bc0, session=0x7fffd4004bc0) at ./src/packet.c:1316 #5 packet_send2 (session=session@entry=0x7fffd4004bc0) at ./src/packet.c:1386 #6 0x77b85315 in ssh_packet_send (session=session@entry=0x7fffd4004bc0) at ./src/packet.c:1411 #7 0x77b72d69 in channel_write_common (channel=0x7fffd40112e0, data=0x7fffdf11fce0, len=6, is_stderr=0) at ./src/channels.c:1357 #8 0x55640cc3 in ?? () #9 0x55644745 in ?? () #10 0x7581de3c in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4 #11 0x7558b6db in start_thread (arg=0x7fffdf1a0700) at pthread_create.c:463 #12 0x74d1388f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 -- Kees Bakker -- / Alexander Bokovoy Sr. Principal Software Engineer Security / Identity Management Engineering Red Hat Limited, Finland ___ FreeIPA-users mailing list -- freeipa-users@lists.fedorahosted.org To unsubscribe send an email to freeipa-users-le...@lists.fedorahosted.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedorahosted.org/archives/list/freeipa-users@lists.fedorahosted.org
[Freeipa-users] Re: ssh ProxyCommand in ipa-client causes crash of x2goclient
On 24-10-19 16:12, Alexander Bokovoy wrote: On to, 24 loka 2019, Kees Bakker via FreeIPA-users wrote: Hey, With x2go [1] you can start a remote desktop. Going from UNIX (client) to UNIX (server) it will use SSH behinds the scenes. However, on a IPA client the x2goclient command fails with a segfault (somewhere in a ssh library). This is caused by the modified /etc/ssh/ssh_config. More specifically this ProxyCommand /usr/bin/sss_ssh_knownhostsproxy -p %p %h When you disable this line the x2go connection succeeds. [1] https://wiki.x2go.org/doku.php If you could install debug packages and generate a backtrace, that would be great as it would help to understand where it happens. Thanks in advance! Hey Alexander, The segfault is in a library of the libssh-4 package. I don't know if that is something you wanted to be involved with. Anyway, here is the stack strace of the segfault. segfault at 4 ip 7f6e7e0d5eeb sp 7f6e64e6ea88 error 6 in libssh.so.4.5.0 After installing the dgbsym package and running from gdb I could get a stack trace Thread 6 "SshMasterConnec" received signal SIGSEGV, Segmentation fault. [Switching to Thread 0x7fffdf1a0700 (LWP 14736)] 0x77b89eeb in ssh_poll_set_events (p=0x7fffd40076b0, events=4) at ./src/poll.c:349 349 ./src/poll.c: No such file or directory. (gdb) where #0 0x77b89eeb in ssh_poll_set_events (p=0x7fffd40076b0, events=4) at ./src/poll.c:349 #1 0x77b8d3c8 in ssh_socket_unbuffered_write (len=, buffer=, s=0x7fffd4003850) at ./src/socket.c:574 #2 ssh_socket_nonblocking_flush (s=s@entry=0x7fffd4003850) at ./src/socket.c:667 #3 0x77b8d4c4 in ssh_socket_write (s=0x7fffd4003850, buffer=, len=len@entry=64) at ./src/socket.c:628 #4 0x77b846c3 in ssh_packet_write (session=0x7fffd4004bc0, session=0x7fffd4004bc0) at ./src/packet.c:1316 #5 packet_send2 (session=session@entry=0x7fffd4004bc0) at ./src/packet.c:1386 #6 0x77b85315 in ssh_packet_send (session=session@entry=0x7fffd4004bc0) at ./src/packet.c:1411 #7 0x77b72d69 in channel_write_common (channel=0x7fffd40112e0, data=0x7fffdf11fce0, len=6, is_stderr=0) at ./src/channels.c:1357 #8 0x55640cc3 in ?? () #9 0x55644745 in ?? () #10 0x7581de3c in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4 #11 0x7558b6db in start_thread (arg=0x7fffdf1a0700) at pthread_create.c:463 #12 0x74d1388f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 -- Kees Bakker ___ FreeIPA-users mailing list -- freeipa-users@lists.fedorahosted.org To unsubscribe send an email to freeipa-users-le...@lists.fedorahosted.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedorahosted.org/archives/list/freeipa-users@lists.fedorahosted.org
[Freeipa-users] Re: ssh ProxyCommand in ipa-client causes crash of x2goclient
On to, 24 loka 2019, Kees Bakker via FreeIPA-users wrote: Hey, With x2go [1] you can start a remote desktop. Going from UNIX (client) to UNIX (server) it will use SSH behinds the scenes. However, on a IPA client the x2goclient command fails with a segfault (somewhere in a ssh library). This is caused by the modified /etc/ssh/ssh_config. More specifically this ProxyCommand /usr/bin/sss_ssh_knownhostsproxy -p %p %h When you disable this line the x2go connection succeeds. [1] https://wiki.x2go.org/doku.php If you could install debug packages and generate a backtrace, that would be great as it would help to understand where it happens. Thanks in advance! -- / Alexander Bokovoy Sr. Principal Software Engineer Security / Identity Management Engineering Red Hat Limited, Finland ___ FreeIPA-users mailing list -- freeipa-users@lists.fedorahosted.org To unsubscribe send an email to freeipa-users-le...@lists.fedorahosted.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedorahosted.org/archives/list/freeipa-users@lists.fedorahosted.org
